How do comets, asteroids, and meteorites influence life on Earth? ... They usually burn up in the atmosphere and look like "fireballs" when they fall to Earth. Approximately 500 meteorites reach Earth's surface each year; they are important because scientists can study what they are made of and where they came from.
Comet: A body of ice, rock, and dust that can be several miles in diameter and orbits the sun. ... Meteor shower: A collection of meteors visible when Earth passes through a trail of debris left by a comet. Asteroid: An object larger than a meteoroid that orbits the sun and is made of rock or metal.
